LAHORE (Pakistan) • Survivors trapped in the rubble of a collapsed Pakistani factory pleaded for help on their cellphones yesterday, even as rescuers said they feared the death toll of 19 could rise in the latest tragedy to highlight poor safety standards in South Asia.

Pakistani rescuers have pulled more than 100 survivors from the rubble and are searching for dozens of others believed to be still trapped.

Soldiers and rescuers in Lahore were carefully cutting through steel and using cranes to lift the debris of the building in a bid to find people still alive, with survivors saying many of the workers were children.

"We were working on the first floor when the roof collapsed," said one of the trapped workers, Mr Liaqat Ali, who used his cellphone to talk to a television station. "Now I can hear the rumble of heavy machines, which gives me hope that I will come out alive."

Medics had to amputate one man's leg on the site before rushing him to hospital. "One of his legs was trapped in such a way that it was not possible to retrieve him with both legs," said an official who did not want to be named. "We had no other option."

One worker still trapped in the rubble told Samaa TV early yesterday that he was pinned under a girder but alive and feeling thirsty.

Families on the scene were struggling to reach the site, crying and at times scuffling with police and soldiers holding them back. "I have to go there, even if they are going to shoot me," an elderly man said.

It was unclear how many people were in the building when it collapsed, or how many - dead or alive - may still be trapped.

Rescue services spokesman Jam Sajjad Hussain said yesterday it was difficult to give a specific number, but added that workers had told officials that around 200 people had been inside the building at the time of the collapse, although that was unconfirmed.

"Rescue work is ongoing and I fear that the death toll may increase," he said.

Factory employee Mohammad Navid said dozens of shift workers may have been sleeping in a section of the building that rescuers have not yet reached, and that children as young as 12 had been working in the factory.

Another employee, 18-year-old Mohammad Irfan, said from his hospital bed that the workers were "mostly" aged between 14 and 25.

Chief doctor Zia Ullah at Jinnah Hospital, where some survivors were taken, said on Wednesday that the majority of victims were young workers, with many suffering head injuries and fractured limbs.

Rescuers were using audio and video technology as they searched. Cranes and machinery provided by the army were also being used.

The collapse occurred at the four-storey Rajput Polyester polythene bag factory in the Sundar industrial estate, around 45km south- west of Lahore's city centre. The factory may have suffered structural damage in the Oct 26 quake that killed almost 400 people across Pakistan and Afghanistan, Punjab Chief Minister Shahbaz Sharif said.

"I have heard about the earthquake affecting the building, but according to labourers, the owner continued to build an extension," he told reporters.

AGENCE FRANCE-PRESSE, REUTERS